Land ice altimetry

CPOM uses radar altimeter data from the ERS-1, ERS-2, Envisat and CryoSat-2 satellite missions to investigate ongoing changes in the Earth’s land ice masses, focusing on Antarctica, Greenland and the Arctic ice caps.

Observing how these ice masses are changing is critical because it tells us how ice melt is affecting global sea levels, and also allows us to investigate, and better understand, how climate change is affecting these vast, yet remote, ice bodies.

We use altimetry to do this because of the level of detail it can provide: a monthly record spanning several decades, with a resolution that allows us to identify changes occurring across individual glaciers or whole ice sheet sectors.

Thanks to CryoSat-2, advances in radar altimetry instrument technology and processing now allow us to study the Antarctic and Greenland ice sheets in unprecedented detail.

In West Antarctica, we are using the long term altimeter record to track the increasing signal of dynamic imbalance, as warm water thins the ice shelves that flow into the Amundsen Sea. We are also using CryoSat’s high resolution to investigate the detailed pattern of melting underneath these ice shelves.

In Greenland, CryoSat has revealed the detailed spatial and temporal pattern of mass loss from the ice sheet. These are being combined with data from climate models to identify “hot-spots”, where glaciers are in a state of dynamic imbalance and rapidly discharging ice into the ocean, and also show how the ice sheet responds to year-to-year variations in the intensity of summer melting.